it's not caused by a heart valve problem. he was taking warfarin, but i've put him on pradaxa instead. in a clinical trial, pradaxa 150 mgs reduced stroke risk 35% more than warfarin without the need for regular blood tests. i sure was glad to hear that. pradaxa can cause serious, sometimes fatal, bleeding. don't take pradaxa if you have abnormal bleeding, and seek immediate medical care for unexpected signs of bleeding, like unusual bruising. pradaxa may increase your bleeding risk if you're 75 or older, have a bleeding condition like stomach ulcers, or take aspirin, nsaids, or bloodthinners, or if you have kidney problems, especially if you take certain medicines. tell your doctor about all medicines you take, any planned medical or dental procedures, and don't stop taking pradaxa without your doctor's approval, as stopping may increase your stroke ri. other side effects include indigestio stomach pain, upset, or burning. pradaxa is progress. if you have afib not caused by a heart valve problem, ask your doctor if you can reduce your risk of stroke with pradaxa.